Comparison of Piperacillin-tazobactam and Vancomycin (TZP-VAN) with Piperacillin-tazobactam and Teicoplanin (TZP-TEI) for the risk of Acute Kidney Injury (CONCOMITANT): A prospective observational, multinational, multi-centre cohort study.

Objectives: Both vancomycin (VAN) and teicoplanin (TEI) augment the risk of acute kidney injury (AKI) when combined with piperacillin-tazobactam (TZP). We aimed to compare the risk of AKI among patients receiving TZP-VAN versus TZP-TEI.

Methods: This was a prospective, multinational, multicentre cohort study conducted in 12 centres from Turkiye, Italy and Spain between June 1, 2022, and December 31, 2023. The primary outcome was the occurrence of acute kidney injury (AKI) between the first day of antibiotic treatment and the third day after completing therapy, according to the Kidney Disease Improving Global Outcomes criteria. Multivariable logistic regression and propensity-score match analyses were employed to adjust for confounding variables. Stratified Kaplan-Meier analysis was used to assess the time-to-AKI between the comparison groups.

Results: Of 187 patients (TZP-TEI, n=102; TZP-VAN, n=85), the AKI occurred in 21 patients (24.7%) who received TZP-VAN and in 15 patients (14.7%) with TZP-TEI (unadjusted odds ratio [OR], 1.90; 95% CI: 0.91-3.97; P= 0.087). After adjusting for confounding variables with multivariable analysis, TZP-VAN was not associated with increased odds of AKI compared with TZP-TEI; with an adjusted OR of 2.24 (95% CI: 0.78-6.42; P= 0.133). In propensity-score matched analysis (n= 49 pairs), the AKI risk was similar between the two groups (OR, 2.10; 95% CI: 0.67-6.50; P= 0.199). The stratified Kaplan-Meier analysis indicated no difference between the treatment groups in terms of time-to-AKI (log-rank test, P=0.107).

Conclusions: The risk of AKI in TZP-VAN was similar to that in TZP-TEI. These results should be confirmed in randomized controlled trials.